Hopper bottom car



April 8, 1941. .1. D. BENBOW ErAl.

HOPPER BOTTOM CAR Filed Aug. 16, 1937 6 Sheets-Sheet l April 8, 1941. J.D. BENBOW ETAL HOPPER BOTTOM CAR 6 Sheets-Sheet 2 Filed Aug. 16. 1957April 8, 1941. J. D. BENBOW El HOPPER some CAR Filed Aug. 16, 1957 6Sheets-s 3 6 Sheets-Sheet 4 J. D. BENBOW ETAL HOPPER BOTTOM CAR FiledAug. 16, 1957 April 8, 1941.

April 8, 1941. J. D. BENBOW ET AL HOIPER BOTTOM CAR Filed Aug. 16, 19376 Sheets-Sheet 5 Ap 1941- J. D. BENBOW ETAL 2.237.299

HOPPER BOTTOM CAR Filed Aug. 16, 1937 6 Sheets-Sheet 6 Patented Apr. 8,1941- norrna no'r'rou can James D. Benbow and George W. Sines, Aurora.

aseiznors to Western-Austin Company,

Aurora, 111., a corporation oi Illinois Application August 16, 1937,Serial No. 159.225

230laims.

Our invention relates particularly to hopper type cars with bottomdischarge doors mounted on trucks for operation on rails, or hoppercontainers mounted on wheels with or without rnbber tires for operationon roads and pulled by tractor trucks, in which the doors or gates arecontrolled by air or any other fluid pressure. In the mining industry,coal mining in particular, the opening and closing of the doors orgates, when dumping the load into ahopper or onto a belt conveyorlocatedunder the track on which the cars operate, has been accomplishedby mechanical means at the discharge point, and the car or the hoppercontainer mounted on rubber tires could not be used to haul refuse orgob on the return trip to the mines and deposit it where the ore or coalhad been removed, as it has been necessary to have the mechanical meanslocated at the place of dumping whenreturning the refuse or gob to themines, which is impractical because the location of the dump isconstantly changing. Our invention permits the opening and closing ofthe doors or gates at any desired place, thus increasing the usefulnessof the hopper car or hopper container mounted on rubber tires. In thedrawings only one pair of doors is shown. However, any number of doorscan be the trunnion or pivot point of the discharge doors or gates thatthe load in the hopper car or the hopper container will assist in theopening of the doors or gates after the unlocking of the doors or gateshas been accomplished.

Another object of our invention is to provide means for controlling theunlocking or opening of the doors or gates from a remote point on thecar.

Another object of this invention is to provide discharge door lockingmeans which'is a part of the pressure cylinder, and the locking meansmust be unlocked before fluid pressure can be admitted to the cylinder.c

Another object of this inventionis to so locate the pivot points of thedischarge doors or gates that they will be self-closing.

Another object of our invention is to provide a fluid pressure cylinderhaving the locking and unlockingmeans made an integral part of the fluidpressure cylinder, whereby the locking and unlocking of the doors arecontrolled by admit. ting or releasing the air or fluid pr'essure meansinto or out of the locking and unlocking means in the cylinder. Fluidpressure means must first be applied to the locking means in thecylinder to unlock the doors before it can be applied to the cylinder.By exhausting the fluid pressure, the

locking means will engage the piston rod of the cylinder when the pistonrod of the cylinder is in an extended position.

Another object of our invention is to provide a fluid pressure cylinderhaving a piston and piston rod mounted therein and a valve located inthe lower cylinder head with a spring actuated locking means and fluidpressure unlocking means, which engages the piston rods to hold thedoors closed when the piston rod is in an extended position. The lockingdevice is so designed that air or any fluid pressure cannot be admittedto the fluid pressure cylinderuntil the locking means has beendisengaged from the piston rod,

, mechanical locking means to lock.the door in a Another object of ourinvention is to provide means for controlling'the unlocking, or theopening andclosing of the doors or gates from a tractor truck orlocomotive by the tractor operator or the locomotive engineer.

Another object of our invention is to provide means whereby the air orfluid pressure means must first unlock the doors or gates before the airor fluid pressure is applied to the door opening means.

Another object of our invention is to provide means whereby the pistonrod can be adjusted as to length to provide for wear, or variations inshop practices.

closed position and fluid pressure means to unlock and open the doors,and a method of mounting the doors on the container so as to make themself-closing.

Further objects of this invention are to provide a construction ofmaximum simplicity, efllciency, economy and ease of assembly andoperation, and such further objects, advantages and capabilities aswill-later more fully appear and are inherently possessed thereby.

, The invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings and, whilewe have shown therein a preferred embodiment, it is to be understoodthat the same is susceptible of modification and change withoutdeparting from the spirit of our invention.

In the drawings:

*tainer mounted on rubber tires, showing Figure 1 is a side elevation ofa hopper car mounted on standard railroad trucks.

'Figure 2 is a cross section of the car, or container, with the doors ina closed position.

Figure 3 is a cross section or the car, or container, with the doors inan open position.

Figure 4 is a diagrammatic drawing showing the piping oi the controlmean for unlocking,

vMining and closing the doors.

Figure 5 is a cross section: of the operating or control valve.

Figure 64s a cross section of the cylinders when the doors are in lockedposition.

Figure 7 is a cross section'of the cylinders when the doors are in openposition.

Figure 8 is a cross section of the door locking valve when the air, orfluid pressure, is being exhausted.

Figure 9 is a side elevation of the hopper, or container mounted onwheels or rubber tires and tractor truck for operation on roads,

I and unlocking valve shown in Figure 12.

piston rod II has groove 20 which is engaged by lock pin or piston rod25 of valve 9 to hold ti" doors 4 in a closed or locked position. Thelow portion or cylinder head 18 has a groove I22 to receive gasket I24and body 19 of cylinder 8 and is bolted by bolts Hi to flange 123 ofcylinder 8.

Cyiindenhead 18 contains the'valve 9 and also has brass bushing I29 andleather air or oil seal I21 and dirt seal I29, which are held in placeby plate I29 with tap screws I39, and is used as a guide for the pistonrod 19. The lower portion 28 of piston rod I0 is threaded to receive aT- shaped tapped nut 29 having holes 19 to receive pins ii, the T-shapednut 29 being tapped to receive the lower threaded portion 28 of pistonrod ll, which provides adjustment for wear as well as adjustment for thelength of the stroke of piston rod I I. Set screw I2! is provided toprevent the turning of T-shaped nut 29 on the lower' threaded portion 22of piston rod 10.

The valve 9 in the lower portion of cylinder head ll consists of a lockpin or piston rod 25 which is upset and threaded to receive washer l1and packing cup II which are held together by nut l9 and lock nut 29.Tube 2| is pressed in the body of valve 9 and has a series of holes 22in the periphery of the tube to permit air to flow from the inlet 25thru the series of holes 22 into cylinder 8. When air or other fluidpressure means is admitted to the cylinder 8 through valve 9 at theinlet 35, it moves the lock pin or piston rod 25 of valve 9 'outward inguide nut 22 thru hole Referring to the drawings, the car hopper andunderframe I, having sides 2, ends 3 and doors 4,

- are supported on the draftbeams 4 and bolsters I by trucks I, whichmay be of any suitable design for operation on rails of any desirabletrack gauge.

Doors 4 are supported and carried by arms l4 which are attached to eachend of doors 4 and are hung from the ends 2 by pins it, which permitsthe oscillation of doors 4 for the opening and closing of the bottom ofthe hopper I. The opening and closing of doors 4 is accomplished bycylinders I which are attached to the sides 2 by pins l2. Piston rodsIll of cylinder 8 are attached to the doors 4 by pins l I.

By referring to Figures 2' and 3, you will note that the doors 4 are sohung or supported on the ends 3 of the hopper I as to be self-closing.Also,

24, compressing spring lit and unlocking the piston rod ll of cylinder 8as shown in-Figure 7. The air or other fluid pressure means is then freeto flow thru the holes 22 into the body of the cylinder and will causethe piston 21 and piston rod III to move upward to the position shown inFigure '7, when air pressure is released from the inlet 35 oi. the valve9, look pin or piston rod 25 and spring lid of the valve 9 return to theposition shown in Figure 8 and the air from the cylinder 0 is releasedthru the holes 22 and into the atmosphere thru the holes I20 oi the nut23 instead of returning thru inlet 35. The piston 21 and piston god I IIare thus permitted to return the doors 4 to the normal position veryquickly and the spring ill moves lockpin or piston rod 25 to engage thepiston rod I II as shown in Figure 6, which is the locked or closedposition oi the doors 4.

to the ends 3 are towards the outside 01' the cenbody or sides 2. Pistonrod II is attached to piston 21 by the threaded portion 12 or the pistonrod II and is prevented from turning, after being screwed in place inpiston 21, by pin 14. Packing cup I! is applied to piston 21 and held inplace by piston follower I6 and cap screws 11. T

The doors 4 have projections 30 with athreaded portion 32 to receive thethreaded pin I iwith adlusting nut 93, which prevents the rotation ofpin Ii but allows the T-shaped nut 29 to oscillate on I each of the pinsH. Pins i i are provided with an Alemite fitting and a hole 34 fulllength thereof to oil or grease the end of pins which engage theT-shaped nut 29 in the recessed hole 19. Other methods of adjusting thelength ot'the piston rod Hi can be used and come within the scope of ourclaims.

The control or 3-way valve 49, a cross section of which-is shown inFigure 5, is similar to the control valve shown and more fullydescribedin 8|, packing cup 82' and retaining washer 88, all held together bybolt 84 which is screwed into a threaded portion of piston rod 8| asshown in Figure 5. The spring 85 holds the piston III in the safetyposition shown in Figure until the. .pressure applied to lever 4| movesthe piston I88 upward and packing cup 82 covers exhaust ports I84,compressing spring 85 to permit air to flow thruthe inlet 6 and holes 88into the body of the control or 3-way valve 48 and thru hole 88 tooutlet 81. I

Automatic valve is shown in cross section in Figure 11 and a similarautomatic valve 44A is shown in Figure 14. A more completedescription'is given in Letters Patent No. 1,481,781 issued to J. D.Benbow January 29, 1924,, and it is body 88 by bolts 88. The completepiston 88 consists of packing follower 53, packing cup 52 and spacer 48,packing cup 8| and spacer 82, packing cup 8l-A and washer 58, which areconnected by bolt 5| and nut 58, forming one unit (piston 86) formovement in the valve body 88. Valve body 88 has brass tube 51 pressedtherein and has three series of holes 58,88 and 84 located in theperiphery thereof. The inlet 45 is connected to the auxiliary airreservoir 86, thereby maintaining constant air pressure above thepacking By the operation of control or 8-way valve 48 (see Fig. 4),moving handle 4| to thedottcd position 42, air from reservoir-88 willflow through control or 3-way valve 48 to the lower portion 54 ofautomatic valve 44 (see Figs. 11 and 14) thru inlet 85, which forces thepiston 88 upward and permits air from reservoir 86 to flow in thru theholes 84 and out through the holes 83 to outlet 41. Returning the valvehandle 4| of the control or 3-way valve 4|! to its normal positionreleases the pressure in the lower portion 54 of the automatic valve 44and the spring 81, combined with the air pressure above the packing8|-A, forces the piston 86 downward 'to the position shown in Figure 11and the air will be exhausted from the outlet 41 back thru the holes 88and outwardly to the atmosphere thru the holes 58 and 88.

Referring to Figures 12, .13 and 14, which illustrate another method oflocking and unlocking the doors 4, automatic valve 44-A, a cross sectionof which is shown in Figure 14, is similarly constructed to automaticvalve 44 shown in Figure 11, except that the bottom head 54 is changedas shown by 54-A of Figure 14. The.

bolt 6| of the automatic valve 44-A is similar to bolt 5| of automaticvalve 44 except that it ismade longer and extends thru leather, oil orair seals 58 in the lower head 54-A and has the and unlocking mechanismas shown in Figures' 12, 13 and 14. Automatic valve 44A is locatedbetween ,the two partition plates 84 (see Figs. 12 and 13) and fastenedthereto by bolts 88 which pm thru the lower portion 54-A of automaticvalve 44-A. The door locking arms 62 are attached to the partitionplates 64 at ends 46 by pins 88, which permits the oscillation of the'door locking arms 82 for locking and unlocking doors 4. Door lockingarms 82 have vertical slotted holes 88 and they are attached to bolt 8|at jaws 88 by pins 68. The door locking arms 62 have projections 61which engage the doors 4 at the lugs 88 which are provided foradjustment of wear. Door locking arms 62 are provided with extensions 88which project thru the sides 2 to permit manual unlocking of the doors 4should some part of the automatic valve 44-A fail to operate.

Referring to Figures 1, 4 and 5 and also to Figure 11 for cross sectionof automatic valve 44, mounted on the car underframe is auxiliary airreservoir 38 which is charged thru some outside source, such as'alocomotive having an air pump, thru'the pipe line 81, which has valve 88for cutting off the air supply when the car is to be disconnected, andcheck valve 88 which prevents air from returning from auxillary air-reservoir 86. Control or 3-way valve 48 is mounted at some convenientplace on either side ofthe car underframe having valve handle 4|, which,when depressed to the dotted lines 42, allows the air to flow fromauxiliary air reservoir 88thru pipe line 81 through inlet |6 to thecontrol or 3-way. valve 48 and pipe line 48 to the lower end 54 .of theautomatic valve 44. Pipe line 45 is connected to the upper part ofautomatic valve 44 and to auxiliary air reservoir 88, thereby keeping aconstant pressure of air on the upper end of the automatic valve 44.When air is applied by the movement of valve handle 4| to the position42, it forces the piston 88 in automatic valve upward and permits theair to flow from the auxiliary air reservoir 38 thru automatic valve 44to pipe 41, thru T 48 and thru pipe lines 48 to the valve 8 of thecylinders 8 on either side of the car body, unlocking piston rod l8 andcausing piston 21 and piston rod l8 to open doors'4. When the valvehandle 4| is returned from position 42 to the full line position ofvalve handle, the air is exhausted from the lower portion of automaticvalve 44, which allows the return of piston 88 to its normal positionand the air in pipe lines 48 is exhausted from valve 8 thru the pipeline 48 and 41 to automatic valve 44 and thru the holes 58 and 88, whichare a series of holes in the periphery of tube 51 and body 88 ofautomatic valve 44, to the atmosphere, permitting the lock pin or pistonrod 25 to return to the position shown in Figure 8. Packing cup l8uncovers holes 22 and allows the air in cylinder 8 to flow to theatmosphere thru exhaust holes I28, and piston 21, piston rod I8 and lockpin or piston rod 25 return to the normal position ence to the hoppercontainer |-A and the tires jaw 68 attached for operating a door lockingill. The parts which are similar to the hopper car shown in Figure 1 aregiven the same reference numbers and the opening and closing of thedoors 4 is accomplished by the cylinders 8 in a similar manner to theopening and closing of the doors 4 in the hopper car I mounted onrailroad trucks 5.

Referring to Figure 11, the dotted lines 8 a portion 54 of automaticvalve 44.

having inlet III, outlet III, exhaust III and valve handle III, and ismounted in the cab ,01 the truck III as shown in Figure 9. III repre-The .valve III can be control valve II or an ordinary 3-way valve sentsair pump located on the truck III, which is power driven and is usuallyconnected to-the engine of the truck III by a flexible belt. The airpump IIII charges the air, reservoir III from which the air pressure isdrawn tocharge the auxiliary air reservoir II located in the front endor the h pper container I-A thru pipe I II, III and chec valve 39.Theair pressure in the auxiliary air reservoir 36 is prevented fromreturning to the atmosphere by check valve II, in the event theautomatic hose connector III is disconnected. I

By moving the valve handle III of the 3-way valve" III to the dottedposition III, air will flow from the air reservoir"! thru pipe IIII,

into the inlet Ill and the outlet III of the valve III, thru pipe III,thru the automatic connector III, thru pipe II into inlet 95 to thelower The air pressure will force the piston II upward, permittingtheair to flow from the auxiliary air reservoir" thru pipe" to the upperpart of the automatic valve II thru the series of holes 94 and II, thruoutlet .41, thru pipe 49 to the valves I of the cylinders I at inlets35, moving the lock pin or piston rod 2' outward, unlocking piston rodII of cylinder I and permitting the air to flow thru the holes 22 intothe body of the cylinder I and force the piston 21 and piston rod IIupward to the position shown in Figure 7, thus opening the doors 4.

the doors I and hold the same in locked position.

Releasing the oil pressure from the upper end oi ders, each door can belocked and unlocked indeplurality of discharge doors, fluid pressurecylinders with pistons, piston rods and piston rod locking and unlockingmeans mounted in the said 1 fluid pressure cylinders mounted on thesides of said hopper bottom dump car, said piston rods connected to saiddischarge doors, control means mounted on said hopper bottom dump car tocontrol the admission of fluid pressure to unlock and open saiddischarge doors and to allow said bottom dump car, fluid pressurecylinders with The closing of the doors is accomplished by returning thevalve handle III from the dotted position II I to the full line positionshown in Figure 11, thus exhausting the air from the pipe lines III andII and from the lower portion 54 of the automatic valve 44, whichpermits the piston II to return'to the original position as shown inFigure 11. Thereby, the air is allowed to flow thru the pipe lines 49and." into the atmosphere thru the exhaust holes II of the automaticvalve II, thus permitting the lock pin or piston, rod 25 of the valve Ito return to the position shown in Figure 8 and releasing the air fromthe cylinder I thru the holes 22 into the atmosphere thru the holes IIIor the nut 23. The piston 21 and piston rod II are thus permitted toreturn the doors I to the normal position and the spring lift causeslock pin or piston rod II to engage the groove 28 of the piston rod IIas shown in Figure 5,

which is ;the locked or closed position oi the doors I.

Other methods may be used to open and close the doors 4, such as oilpressure using a 4-way valve instead of the 3-way'or control valves IIIand III and an hydraulic pump with power means connected to the tractionengine for operating the pump. Piston 2! of cylinder I can be suppliedwith an additional packing cup inthe reverse oi' the position of packingcup ll, having two pipe lines leading from the control valve II or IIIand connecting the upper and lower ends of cylinder I. Admitting oilunder pressure to the upper end of piston 21 of cylinder I, will closepistons, piston" rods, automatic door locking means and fluid pressureunlocking means mounted in said cylinders pivotally mounted on the sidesof said hopper bottom dump car, said piston rods connected to saiddischarge doors, control means on said hopper bottom dump car to controlthe admission oi fluid pressure to the said fluid pressure cylinders andsaid fluid pressure door unlocking means to unlock said automaticdoorlocking means which contacts the said doors to close, and the saidautomatic door looking means to engage the said piston rods and lock thesaid doors in a closed position. v

3. In a hopper bottom dump car, in combination, discharge doors mountedon .said hopper bottom dump car, fluid pressure cylinders with pistonsand piston rods mounted therein mounted on said hopper bottom dump car,said piston rods connected to said discharge doors, means mounted insaid pressure cylinders to engage and lock position. a

4. In a hopper bottom dump car having selfclosing sidewise swingingdoors pivotally mounted on the ends of said hopper bottom dump car toclose the hopper opening, fluid pressure cylinders with pistons, pistonrods, automatic piston rod locking means and fluid pressure unlockingmeans mounted in said fluid pressure cylinders mounted on the sides ofsaid hopper bottom dump oar, said piston rods connected to said doors,control means on said hopper bottom dump car to control the admission offluid pressure to said fluid pressure-unlocking means and cylinders tounlock and open-the said doors and to release fluid pressure in saidcylinders and said fluid pressure unlocking means and allow the force ofgravity to close said doors and the said automatic locking means operateand lock said doors in pressure cylinders mounted on the hopper sides ofsaid hopper bottom dump car, said piston rods connected to said doors,means mounted on said hopper bottom dump car to control the admissionand release or fluid pressure which actuates the pistons and springactuated piston rod looking means and said fluid pressure cylinders tounlock, open, close and lock the said doors.

6. In a railway dump car or container, hav

ingdischarge doors, fluid pressure cylinders with pistons and pistonrods. mounted therein mounted on said car or container, said piston rodsconnected to said doors, spring actuated door looking means engagingsaid piston rods to hold said doors closed, fluid pressure unlockingmeans mounted in the cylinder head of the said fluid pressure cylinders,control means on said dump car or container to control the admission offluid pressure to said fluid pressure unlocking means and said cylindersto unlock and open the said doors and to release the fluid pressure inthe said fluid pressure cylinders and the said fluid pressure unlockingmeans to allow said doors to close and the said spring actuated doorlocking means to lock said doors in a closed position.

7. In a hopper bottom dump car, having selfclosing sidewise swingingdoors pivotally mounted on the hopper ends of said hopper bottom dumpcar, fluid pressure cylinders with pistons and piston rods mountedtherein mounted on said hopper bottom dump car, said piston rodsconnected I to said doors, spring actuated door locking means engagingsaid piston rods and fluid pressure unlocking means mounted in thecylinder heads of the said fluid pressure cylinders, control means onthe said hopper bottom dump car to control the admission or fluidpressure to said fluid pressure in locking means and said fluid pressurecylinders to unlock and open the said doors and to control the releaseof the fluid pressure in the said fluid pressure cylinders and the saidunlocking means and allow the said doors to close and the said springactuated door locking means to engage the extended said piston rod andlock the said doors in a closed position.

8. In a hopper container, in combination, supporting means for saidhopper container for movement over the road, tractor truck connected tosaid hopper container supporting means, said closed, remote controlmeans to control the unlocking of said power locking means and saidpower opening means to open said doors.

10. A hopper container with supporting means for movement over theground, in combination, a pair of gravity closing doors swingablysupported at the ends oi! said hopper container, fluid pressurecylinders with pistons, piston rods and piston rod locking mechanismmounted in'said cylinders mounted on said hopper container, said pistonrods connected to said doors, control means to control the movement oi!fluid pressure to the said piston rod locking mechanism and fluidpressure cylinders and control the movements of the said pistons andlocking mechanisms when opening and closing said doors.

11. In a container having sloping sides and ends with openings atthe-bottom thereof, in combination, supporting means for said containerfor movement over the road, doors pivotally mounted at the ends of thesaid container to close said openings, fluid pressure cylinders havingpistons,

wadjustably and pivotally connected to said dis-,

ing fluid connection means to said hopper con- 1 in combination,multiple doors at the bottom of said container, power opening andclosing means attached to said hopper container and to said doors, powerlocking means attached to said power opening and closing means to holdsaid doors piston rods and locking means for said piston rods mounted insaid cylinders mounted on the sides or said container, said piston rodsconnected to said doors, and said piston rod locking means engages andlocks the said piston rods in the extended position to hold the doorsclosed.

12. In a railway hopper bottom dump car, a plurality of discharge doors,fluid pressure cylinders with pistons, piston rods and door lockingmeans mounted therein pivotally mounted on said hopper bottom dump car,said piston rods are charge doors, control means mounted on said .hopperbottom dump car to control the admission of fluid pressure to said doorlocking means and said cylinders to unlock the door locking means andopen said doors.

13. In a hopper bottom container with bottom openings, supporting meansfor said container for movement over the road, self-closing doors toclose said bottom opening swingably mounted on the ends of saidcontainer, fluid pressure cylinders with pistons and piston rods mountedtherein swingably mounted on the sides of said container, one end ofsaid piston rods pivotally connected to said doors, fluid pressure doorunlocking means and automatic door locking means mounted on saidcontainer, said automatic door locking means locks said doors when saiddoors are in a closed position, control means on said hopper bottomcontainer supporting means to control the admission of fluid pressurefrom the fluid pressure reservoir mounted on said supporting means, tothe-said door unlocking means to unlock said doors and to said cylindersto open said doors and to control the release of said fluid pressure toallow said doors to close and automatically lock.

14. A hopper container with bottom openings, in combination, supportingmeans for movement of said hopper container over the ground, gravityclosing bottom doors to close said bottom open,- ings swingably mountedon said container, fluid pressure cylinders with pistons and adjustablepiston rods mounted therein swingably mounted on said container, saidpiston rods pivotally connected to said doors, fluid pressure unlockingand locking means mounted in the heads oi. said cylinders with means toengage said piston rods when in an extended position to hold said doorsin a closed position, control means mounted on said containersupporting. means to control the admission of fluid pressure to saidunlocking means tohold said doors in a closed position, remote fluidpressure control means having fluid pressure connection to said lockingand unlocking means and said cylinders to control the unlocking andopening of said doors and to release the fluid pressure and allow thedoors to close and lock.

16. A hopper container having bottom discharge doors mounted on the endsthereoi with supporting means for movement of said container inders withpistons and piston rods pivotally mounted on the sides of said hopperbottom container, door locking and unlocking means mounted in thecylinder heads of said fluid pressure' cylinders, said piston rodspivotally connected to said bottom discharge doors, remote means tocontrol the unlocking and the admission of fluid pressure to the saidfluid pressure cylinders to open said doors, and to control thereleasing oi fluid pressure in said fluid pressure cylinders to allow.said doors to close and be locked.

' 20. A hopper bottom container with bottom openings and means tosupport and move said hopper bottom container, in combination,-discharge doors mounted on said hopper bottom container to close saidbottom openings, fluid pres,- sure, cylinders with pistons and pistonrods mounted therein mounted on said hopper bottom over the road, incombination, a self-propelling power unit attached to said container,fluid pressure cylinders with pistons, piston rods and door locking andunlocking means. mounted therein swingably mounted on the sides of saidcontainer,

said piston rods pivotally connected to said doors, control meansmounted on said propelling unit having fluid pressure connection to saiddoor locking and unlocking means and to said cylinders to control theunlocking and opening or said doors and allow said doors to close andlock.

17. A hopper container having self-closing bottom discharge doors withsupporting means for movement of said container over the road, incombination, fluid pressure unlocking and automatic locking meansmounted at the bottom of said hopper container above said doors and saidlocking means contacting said doors, fluid pressure cylinders withpistons and piston rods mounted therein swingably mounted on the sidesor said hopper container, one end of said piston rods pivotallyconnectedto said doors, fluid pressure control means mounted on saidhopper container supporting means having fluid pressure connection tosaid unlocking means and to said cylinders to control the unlocking andopening 01' the said doors and to release said fluid pressure toautomatically close and lock said doors. 1

' 18. A hopper container having swinging doo mounted at the bottomthereof, in combination, rolling supporting means formovement of saidhopper container, a self-propelled traction unit having an operator'sstation mounted thereon attached to said supporting means, fluidpressure cylinders with pistons, piston rods, spring locking means andfluid pressure unlocking means mounted therein swingably mounted on thesides of said container, said piston rods pivotally connected to saiddoors, said spring lockingmeans engaging said piston rods when doors areclosed, automatic valves to admit fluid pressure 'to the unlocking meansand cylinders mounted on said container supporting means, fluid pressurecontrol valves mounted at said operator's station of said traction unithaving fluid pressure connectcontainer, said piston rods connectedto'said discharge doors, means mounted in said pressure cylinderstoengage and lock said piston rods when said piston rods are in anextended position to hold said doors in a. closed position.

21. A hopper bottom container with bottom openings and means to supportandmove said hopper bottom container, in combination, discharge doorsmounted on said hopper bottom container toclose said bottomopenings,fluid pressure cylinders with pistons and piston rods mounted thereinmounted on said hopper bottom container, said piston rods connected tosaid discharge doors, means mounted in said pressure cylinders to engageand lock said piston rods when said piston rods are in an extendedposition to hold said doors in a closed position,

remote control means to control the unlocking or. v said door lockingmeans and permit fluid pressure to enter the said fluid pressurecylinders and open said doors, and to control the release of fluidpressure from said fluid pressure cylinders and permit the doors toclose and be locked.

22. In a hopper bottom container with swingable doors to close thebottom -01 said hopper bottom container, in combination, means tosupport and move said hopper bottom container, fluid pressure cylindershaving pistons, piston rods, locking and unlocking means mounted in saidcylinders mounted on the said hopper bottom container, said piston rodsconnected to said doors, means to control the unlocking and admit fluidpressure to said cylinders to open said ddors, and to control thereleasing of thefluid pressure from said cylinders to allow the doors toclose andbe locked.

'23. In a hopper bottom container with swingable doorsto close thebottom of said hopper bottom container, in combination, meansto supportand move said hopper bottom container, fluid pressure cylinders havingpistons, piston rods, spring locking and fluid pressure unlocking meansmounted in said cylinders mounted on said hop- 1 per bottom ,container,said piston rods connected.-

ing means to said automatic valves, unlocking to said doors, means tocontrol the admission oi fluid pressure to the saidunlocking means andsaid cylinders to open said doors and to control the release or saidfluid pressure in said cylinders and unlocking means to allow the doorsto close and the said spring locking means to lock said,

door in a closed position.

' JAMES D. BENBOW.

GEORGE W. SINES.

